Metal heating furnace



Aug. 13, 1963 F. s. BLOOM METAL HEATING FURNACE Filed May 31, 1960 INVENTOR Frederick S. Bloom lective transverse heating is Vincrease the production ot furnace ,ment causing a .holdup therein n .example vof sucha,cooperative-[functioning .ofa transverse ,is working virtually V-Such will -place Va severe ,load

.-less as desired, and quickly, in

ya4 higher work temperature i and have 3 face, which isla surface of revolution having an axis normal to hearth 24. A direct ftring radiant'burner 40 closes the central opening through each port block 38 and discharges fuel and combustion air generally laterally along the surface 39 of the port block for combustion of such fuel and air in a high thermal rele-ase manner causing the Asurface of the port block facing the work 11 to incandesce at relatively high temperature and selectively heat the workpieceportion exposed to av particular radiant burner. The area on the work see11by a particular burner is more heated because of the thermal radiation transmit-ted to thework in :general accordance with the Stefan-Boltzmann law.

The openings 37 .in the embodiment shown in FIG- URES 1 andk 2 are #arranged in longitudinally extending parallel columns. The respective axes of each are -in verti- .calparallelplanes containing the respective longitudinally ,extending skid supports 29.` Hence, such columns, the lateral spacing yof which is shown in FIGURE 2, are in longitudinal alignment with those rails and lselectively heat the topsof slabs 1-1 in longitudinally extending strips to Va .higher intensity .directly pover the longitudinal -skid .mark streaks, than the portions n ,appearing duringlsoaking with corresponding `temperature lower iring rate and then having rearwardly succeeding transverse rows at respectively higher thermal outputs dependent upon the thermal input needs of the workpiece or workpieces exposed to each transverse row of radiant rburners above. Such thermal radiation of radiant 'burners is fast-acting, intense and quickly increased, or decreased, as the nish temperature needs of the workpieces may As a further example, in the processing of quality steel such Ias high carbon steel for |ball bearing metal, and of many stainless steel grades subject to deterioration if held at high temperatures for too` long a time, it normally is desirable to heat such material to 4temperatures in .the neighborhood of 1650 F. and then to raise that temperature as fast as possible to final rolling temperature.

Such rise to final rolling temperature `can readily bey achieved relatively quickly, simply and economically in Y section 15 hy utilization of the lradiant burners'40 in Y of the workpieces yalong- (side such'stripes. `As a .consequence, skid marks resulting cequalization .the .workpieces continue their passage through the furnace vandto the next operation.

` Further, .theiopenings .37 .and vthe radiant burners are arranged in longitudinally succeeding transverse rows, the spacingfofwhich is shown ink FIGURE `1. .transverse row hasthe ability of being operated .at a predetermined liring` level. of

mentation -artjt'o'r employment therewith. Each transverse .row seesla vparticular cross `portion of the workpiece line i ,therebeneathfand is capable of .providing selective transiformll delayror `mechanical troublesinthe furnace equip- .character of so much ,of 4the thermal head .due tozeach ,transverse rowof radiantburnersdllas the `blooms move '.overQhearth 24 during `the period Aof .their exposure .suc- '..cessively .to ,each .transverse row.

In this way, there :is the .desirable flexibility lin vthe heating .the steel more or .the soaking section, in respect .of workpieces whichareto 4receive moreheat-than ,the ,quantity ,imparted vin the -heating sections to provide upon .discharge 4than .would otherwise ipreva'il. With each transverse row of burners independently .regulatable :in accordance with suit-able 'available instrumentation, the soaking section 1S can Vhe "ntilized as la llexible, selective, predetermined Ytemperature .control for the work.

should workpieces 4he held up vinfurnace `a tendency to v become overheated, .such tendency can he quickly -curbed and controlled againby selectiveV regulation of the transverse rows as by turning Conversely,

down the transverse row nearest heating section 12 to a -10 or to compensateY tot workpieces. As .an

Each such l u its own rdepending upon the instrumentation selected bythose Skil-led in the instru- -in said roof with circular flaring `ers being arrangedin longitudinal Vcolumn being in alignment with .in alignment with said skid rail roof 21. *Y The foregoing is illustrative of the wide range and flexibility of temperature control obtainable 'bya'practice of my invention inclusive of the removal of skid `thereinas shown, with a central opening tothe outside of the. slab for the respective burner 40', or separate port block openings may be provided in such roof 21. Each burner 4d sees a larger area because .the flare of the port .block cavity terminates substantially ush with the underside of roof 21'. Burners 40 are arranged .in trans- `verse rows and longitudinally extending ycolumns as in the case of the preceding embodiment, with, however, the burners being shown closer together and covering substantially the whole of hearth 24'. vWith a greater number .of such burners, temperature control vrange and ilexibility is correspondingly increased.

'Various modifications may .be made in details .of the illustratedembodiment, and other embodiments provided, without departing from .the spirit of my invention or .the scope of the appended claims.

I claim: f

1. IIn a direct-fired metal heating furnace, vapparatus compiising, in combination, a heatingsectionhaving Vlongitudinally extending'parallel .cooled skid .rail supports therein, a soaking section lfollowing said .heating section, a refractory hearth in said soakingsection, a'roof in said section substantially parallel .to said hearth and relatively close thereto, a plurality of direct firing radiant burners port block radiant .heat- -ing surfaces having axes fnormal to said hearth, `said burncolumns .with one such but Vlongitudinally displaced relation to each said skid rail support respectively, said axes in each column being in a vertical plane passing through its ,respective skid rail support, said burners Nfurther being arranged in longitudinally successive transverse rows, said radiant burner being operable ,at yselec- .tive thermal input levels to provide heating to a material extent by i radiation in and adjacent their respective planes, whereby heating vby said burners .in said columns supports supplies radiant heat downwardly and more intensively in Ylongitudinal `stripes to remove skid Amarks directly under said stripes on the underside of workpieces on said hearth by conduction through said workpieces, and, said transverse rows of burner supply heat in cross alignmentfurther to provide a selected input for Workpieces exposed to saidV rows respectively for temperature control of said workpieces in said soaking section.

2. In a direct-fired metal heating furnace to prepare ferrous or alloy metal shapes for hot rolling or the like, apparatus comprising, in combination, a heating section having longitudinally extending cooled skid rail supports therein, a soaking section following said heating section and having a hearth and a horizontal roof above said hearth, a plurality of direct ring radiant burners in said roof directed toward said hearth and substantially normal thereto, said burners being respectively arranged in longitudinal columns with at least one burner in each colurnn and each such column being in alignment with but longitudinally displaced relation to each said skid rail support, said radiant burners being selectively operable to provide heating to a material extent by radiation in said respective longitudinal columns normal to said hearth, whereby heating by said burners in said columns in alignment with said skid rail supports supplies radiant heat downwardly and more intensively in longitudinal stripes to remove skid marks substantially directly under said stripes on the underside of workpieces on said hearth by conduction through said workpieces.

3. A direct-tired metal heating furnace as` set forth in claim 2 having said burners further arranged in longitudinally spaced transverse rows, whereby said transverse rows selectively heat workpieces exposed thereto respectively for flexible control additionally of the predetermined finish temperature of said workpieces.

References Cited in the le of this patent i UNITED STATES PATENTS 1,535,132 Renkin Apr. 28, 1925 2,056,904 Morton et al. Oct. 6, 1936 2,180,089 McDermott Nov. 14, 1939 2,776,128 Nesbitt et al. Ian. 1, 1957 2,848,207 Rusciano ---n Aug. 19, 1958 2,872,175 Guenzi Feb. 3, 1959 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No (100,811 August 13, 1963 Frederick S. Bloom It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column l, line 413u after "capacity" insert rolling column 5, line after "a" second occurrenceY insert generally Signed and sealed this 31st day of March 194 (SEAL) Attest: ERNEST W. SWIDER EDXJARD .1. BRENNER Attesting Officer Commissioner of Patents 

1. IN A DIRECT-FIRED METAL HEATING FURNACE, APPARATUS COMPRISING, IN COMBINATION, A HEATING SECTION HAVING LONGITUDINAL EXTENDING PARALLEL COOLED SKID RAIL SUPPORTS THEREIN, A SOAKING SECTION FOLLOWING SAID HEAT SECTION A REFRACTORY HEART IN SAID SOAKING SECTION, A ROOF IN SAID SECTION SUBSTANTIALLY PARALLEL TO SAID HEALTH AND RELATIVELY CLOSE THERETO, A PLURALITY OF DIRECT FIRING RADIANT BURNERS IN SAID THERETO, A PLURALITY OF DIRECT FIRING RADIANT BURNERS IN SAID ROOF WITH CIRCULAR FLARING PORT BLOCK RADIANT HEATING SURFACES HAVING AXES NORMAL TO SAID HEARTH, SAID BURNERS BEING ARRANGED IN LONGITUDINAL COLUMNS WITH ONE SUCH COLUMN BEING IN ALIGNMENTS WITH BUT LONGITUDINALLT DISPLACED RELATION TO EACH SAID SKID RAIL SUPPORT RESPECTIVELY, SAID AXES IN EACH COLUMN BEING IN A VERTICAL PLANE PASSING THROUGH ITS RESPECTIVE SKID RAIL SUPPORT, SAID BURNERS FURTHER BEING ARRANGED IN LONGITUDINALLY SUCCESSIVE TRANSVERSE, ROWS, RADIANT BURNER BEING OPERABLE AT SELEC- 